A disgruntled quake claimant battling the Earthquake Commission has today been found guilty of squirting paint stripper over staff cars parked outside its Christchurch offices.

Semi-retired Christchurch painter and decorator Russell Taylor Carr, 57, had admitted being in dispute with the much-maligned Crown entity for more than two years over a quake-damaged property but vehemently denied the vandalism allegations.

During a judge-alone trial at Christchurch District Court last month, Carr said "extensive problems" with the Earthquake Commission (EQC), including allegations that it accused him of lying and falsifying documentation, led to a complaint being lodged with the Office of the Ombudsman. He ended up enlisting a claims advocate to deal with EQC on his behalf.

Today, Judge Stephen O'Driscoll delivered his reserved judgment over claims Carr had driven his white van past EQC cars and sprayed what experts concluded was paint stripper or similar industrial solvent.

EQC, which still has 2624 claims remaining from the devastating Canterbury earthquake sequence, says its vehicles had been vandalised twice in 2015, which prompted it to install CCTV in their staff carpark.

Shortly before 11am on July 1, 2016 a white van was recorded on security cameras driving past staff vehicles.

Grainy footage seen by the Herald shows a clear liquid coming from the passing driver's window and splashing onto EQC cars and utes.

Two staff members say they saw the same white van return a week later.

Kevin Currie, then EQC manager of investigations and quality assurance based at Barry Hogan Place in the Addington area of Christchurch, filmed it on his cellphone and passed the footage to police.

After the vandalism, EQC contacted chemical risk management firm Chemsafety to analyse the liquid.

Senior chemical consultant Janet Connochie visited the scene and collected three samples.

She noted that paint had disintegrated and laboratory tests concluded the substance to have been paint stripper or similar industrial solvent.

Constable Tony Hickland interviewed Carr four weeks later and showed him CCTV footage of a white van at EQC and liquid being sprayed from the driver's window. He suggested to Carr that it was his cellphone number painted on the side of the van, along with R.T. CARR Decorators Ltd.

When the allegations were put to Carr, he said: "Ooh that's nice. Well, it wasn't me."

He repeatedly denied the claims, and although he admitted he didn't like EQC, like thousands of Cantabrians, he said: "I'm not lowering myself to their levels."

Crown prosecutor Donald Matthews said it was a circumstantial case that when all the strands were put together it led to Carr being the culprit.

But defence counsel Josh Lucas said there was insufficient evidence to prove it had been Carr.

In cross-examination, Lucas asked Hickland if he was aware there was a face on the planet Mars.

After some clarification, Lucas suggested that the policeman was looking at CCTV footage with hindsight, and only then seeing Carr's name and number, but in reality there were only white "hazy blotches".

Judge O'Driscoll said his assessment of the case against Carr came down to looking at the CCTV footage of July 1.

He concluded that Carr was the driver of the van that sprayed the EQC vehicles that day.

"I am satisfied the driver squirted liquid containing a substance consistent with a commercial paint stripper," Judge O'Driscoll said.

"My conclusion is that the defendant had the motive to commit the offence, the opportunity to commit the offence and the ability to commit the offence."